basic TV question

D

default

Guest
Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set
--
 
default wrote:
Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set
My tv, and my 7 crt's give a nice "boing" when swithed on,
Click to expand...
so there must be something wrong with your tv.
There sould be a coil around the front of the tube, and a relay and ptc
resistor to let the current trough that coil fade away to zero.
That somewhat de-gauses your screen.
But only if it works.
Very big errors need an external paddle de-gauser.
 
"default"
Do all TV's have built in degaussing coils these days?
Click to expand...

** All colour TVs and monitors that use CRTs have them.

It's essential.


I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?
Click to expand...

** Most degaussing coils make a bit of noise when the screen is switched
on - but some may be very nearly silent.

Your problem is that the PTC thermistor circuit that drives the coil has
failed.

May be because of the PTC device itself, a blown fuse or a bad connection to
the coil.



..... Phil
 
On Thu, 03 Jun 2010 20:16:52 -0400, default <default@defaulter.net>
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set
Click to expand...
Do you have a soldering gun? They are good degaussers.

John
 
On Fri, 04 Jun 2010 12:22:17 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 03 Jun 2010 20:16:52 -0400, default <default@defaulter.net
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John
Click to expand...
Thanks

I do, and tried that. Winding a coil and connecting it in place of
the tip may be a winner. The gun alone, with a regular soldering tip,
tried in all orientations, did help - the side bands are almost gone
and the center (where I didn't think there was a problem) looks
better.

But there are still two pesky areas on the bottom corners. If I
didn't know better, I'd be looking for a hidden magnet.


--
 
"default" <default@defaulter.net> wrote in message
news:ht2j0658sslr81b2rpkd9ur52cjccd9a8r@4ax.com...
On Fri, 04 Jun 2010 12:22:17 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 03 Jun 2010 20:16:52 -0400, default <default@defaulter.net
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John

Thanks

I do, and tried that. Winding a coil and connecting it in place of
the tip may be a winner. The gun alone, with a regular soldering tip,
tried in all orientations, did help - the side bands are almost gone
and the center (where I didn't think there was a problem) looks
better.

But there are still two pesky areas on the bottom corners. If I
didn't know better, I'd be looking for a hidden magnet.


--
Click to expand...
Just fix the TV.
 
On 06/04/2010 04:34 PM, default wrote:
On Fri, 04 Jun 2010 12:22:17 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 03 Jun 2010 20:16:52 -0400, default<default@defaulter.net
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John

Thanks

I do, and tried that. Winding a coil and connecting it in place of
the tip may be a winner. The gun alone, with a regular soldering tip,
tried in all orientations, did help - the side bands are almost gone
and the center (where I didn't think there was a problem) looks
better.

But there are still two pesky areas on the bottom corners. If I
didn't know better, I'd be looking for a hidden magnet.


Do you have kids? "Hidden magnet" just made me think of that for some
Click to expand...
reason.

Just fix the dang thing.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com
 
On Jun 4, 3:22 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Thu, 03 Jun 2010 20:16:52 -0400, default <defa...@defaulter.net
wrote:





Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing  "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound,  but didn't think anything of it until the
purity started to go out.  Could I have skated this long without a
problem with no built-in coil?  And can they make them totally silent?

Plan A is to whip up a manual degaussing coil.  I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John- Hide quoted text -

- Show quoted text -
Click to expand...
I never thought of that, I was cobbing something together the other
day to demagnetize some tweezers.

George H.
 
On Fri, 04 Jun 2010 19:34:27 -0400, default
<default@defaulter.net> wrote:
But there are still two pesky areas on the bottom corners. If I
didn't know better, I'd be looking for a hidden magnet.
Click to expand...
Hmm, could they be due to the speakers in the set
itself, or a nearby stereo?

Best regards,


Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!
 
On Fri, 4 Jun 2010 20:40:52 -0400, "Tom Biasi"
<tombiasi@optonline.net> wrote:

"default" <default@defaulter.net> wrote in message
news:ht2j0658sslr81b2rpkd9ur52cjccd9a8r@4ax.com...
On Fri, 04 Jun 2010 12:22:17 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 03 Jun 2010 20:16:52 -0400, default <default@defaulter.net
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound, but didn't think anything of it until the
purity started to go out. Could I have skated this long without a
problem with no built-in coil? And can they make them totally silent?

Plan A is to whip up a manual degaussing coil. I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John

Thanks

I do, and tried that. Winding a coil and connecting it in place of
the tip may be a winner. The gun alone, with a regular soldering tip,
tried in all orientations, did help - the side bands are almost gone
and the center (where I didn't think there was a problem) looks
better.

But there are still two pesky areas on the bottom corners. If I
didn't know better, I'd be looking for a hidden magnet.


--

Just fix the TV.


Now where's the fun in that? It is a big beast and I don't want to
Click to expand...
move it.

Calculating the inductance for a degausser is more rewarding than
poking about in TVs.
--
 
On Fri, 04 Jun 2010 21:26:40 -0700, Tim Wescott <tim@seemywebsite.now>
wrote:

Do you have kids? "Hidden magnet" just made me think of that for some
reason.

Just fix the dang thing.
Click to expand...
No kids or magnets that I see. Speakers inside the set have magnets
no doubt.

Fixing is a less desirable option. Ages ago I repaired TVs for a
living. Good chance that if it needs any part it will have to be
ordered, since there are no parts outlets around here. It is a large
beast. Could just be a fuse . . .
--
 
On Jun 5, 5:32 am, default <defa...@defaulter.net> wrote:
On Fri, 4 Jun 2010 20:40:52 -0400, "Tom Biasi"





tombi...@optonline.net> wrote:

"default" <defa...@defaulter.net> wrote in message
news:ht2j0658sslr81b2rpkd9ur52cjccd9a8r@4ax.com...
On Fri, 04 Jun 2010 12:22:17 -0700, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:

On Thu, 03 Jun 2010 20:16:52 -0400, default <defa...@defaulter.net
wrote:

Do all TV's have built in degaussing coils these days?

I have a CRT style TV that's been in service for ~ 4 years and it has
been gradually losing  "color purity" mostly on the bottom edges in a
circular pattern - center good.

I can null out the green or magenta it favors and correct the color by
holding a piece of non-magnetized iron in just the right place in
front of the screen, one corner at a time, so I'm fairly sure it is a
problem with a magnetized chassis or color mask.

I've never heard a 60 cycle buzz when the set fires up the way normal
degaussing circuits sound,  but didn't think anything of it until the
purity started to go out.  Could I have skated this long without a
problem with no built-in coil?  And can they make them totally silent?

Plan A is to whip up a manual degaussing coil.  I have 5,000 feet of
24 AWG and figure 3,000 feet on a 14" diameter coil will have a
reasonable impedance and use ~60 watts.

Plan B is to fix the set

Do you have a soldering gun? They are good degaussers.

John

Thanks

I do, and tried that.  Winding a coil and connecting it in place of
the tip may be a winner.  The gun alone, with a regular soldering tip,
tried in all orientations, did help - the side bands are almost gone
and the center (where I didn't think there was a problem) looks
better.

But there are still two pesky areas on the bottom corners.  If I
didn't know better, I'd be looking for a hidden magnet.

--

Just fix the TV.

Now where's the fun in that?  It is a big beast and I don't want to
move it.

Calculating the inductance for a degausser is more rewarding than
poking about in TVs.  
--
Click to expand...
We had a cheapy Daewoo set for the kids where the degausser failed. It
has a relay on the main board that flexes the contacts slightly when
it actuates. The solder joint eventually failed and all it took to
restore it was to clean off the remaining solder and re-solder it.
Works fine again.

G˛
 
default schrieb:
....> Fixing is a less desirable option. Ages ago I repaired TVs for a
living. Good chance that if it needs any part it will have to be
ordered, since there are no parts outlets around here. It is a large
beast. Could just be a fuse . . .
Click to expand...
unlikely, PTC is more likely.

Some time ago, I had a similar problem:
Built in degaussing didn´t work and the PTC sat inaccessible below the
very large CRT (>30").
I took the degaussing coil and circuitry (which was fortunately on a
seperate print) from an old set set, which was scrapped at this time.
I held the coil in front of the TV and moved it away slowly, the way it
was done before built-in degaussing was standard (prior to ~1960)
(I know this from american literature only, the first color-TVs in
central europe allready hat built-in degaussing (~1967)

greetings, Rudolf
 
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